1. Field of Invention
The present invention relates to a driving apparatus, and more particularly, to a driving apparatus capable of solving the fan-out phenomenon of a display panel.
2. Description of Related Art
If the user does not turn off the power of the backlight of the display panel, but only turns off the signals and the power of the signals when shutting down the computer host, the displayed picture on the display panel will be disappearing with an extremely slow speed. On the contrast, if the power of the backlight, the signals and the power of the signals are all turned off when shutting down the host, faint changes of the light and shadow still occur like tides on the display panel, that is, the fan-out phenomenon caused by different discharging speed of each pixel transistor due to uneven film thicknesses of the thin film transistors in the display panel. In particular, at the instance of turning off the power, different film thicknesses of the thin film transistors resulting in different capacitances, such that the required discharging time is different, and thus, the time for liquid crystals to rotate and recover is different, thereby causing a ghost picture as ebb tide to occur on the panel.
Therefore, in order to eliminate the fan-out phenomenon, some display panel designers and manufacturers provide several solutions of this problem, as shown in FIG. 1 and FIG. 2. FIG. 1 is a block diagram of an architecture of a conventional gate driver, and FIG. 2 is a signal timing diagram of the conventional gate driver. Refer to FIG. 1 and FIG. 2 for the illustration.
Referring to FIG. 1, an input buffer 101, a shift register 102, a level shifter 103, an output buffer 104 and a reset circuit 105 are shown. The input buffer 101 is used to buffer a clock signal CPV, a start signal STV, an output enable signal OE and a full output enable signal Xon. The shift register 102 generates N shift signals according to the clock signal CPV and the start signal STV, and then, outputs the N shift signals according to the output enable signal OE, so as to form N output signals. The level shifter 103 receives and shifts the signal levels of the N output signals, and then, outputs the N output signals with shifted signal levels after being buffered by the output buffer 104, i.e., OUT1-OUTN respectively, so as to sequentially drive the gates line G1-GN (not shown) of the display panel.
Referring to FIG. 1 and FIG. 2, when the user shuts down the computer, the shift register 102 generates N output signals simultaneously according to the full output enable signal Xon (as shown by 201 in FIG. 2) output by the reset circuit 105, and the gate driver further outputs N output signals OUT1-OUTN-1, OUTN simultaneously (as shown by 202 in FIG. 2), so as to drive the gate lines G1-GN of the display panel simultaneously. Therefore, the fan-out phenomenon caused by different discharging speed of each pixel transistor in the display panel is eliminated.
However, the full output enable signal Xon must be controlled by the reset circuit 105 on the printed circuit board (PCB) of the display panel, and the reset circuit 105 employs the existed reset IC, thus, if the conventional architecture as shown in FIG. 1 is used to eliminate the fan-out phenomenon, not only the reset IC is additionally used on the PCB, causing the burden of the manufacturing cost, but additional PCB wiring is also required for the reset IC, as a result, the design and manufacturing of the display panel becomes time consuming and labor intensive, which is quite disadvantageous to those display panel manufacturers who want to reduce the manufacturing cost and increase the profit of products.